Improvement in valve-gears for engines



n. Msc. FRYER.y

Valve-Gears for Engines. Y

VNo.2,f135,796. y Patemedfeb-ln,1,8,73.

AMnioro-umocmvmc co. Mwomamvz mams) the pistons NunnS'IA'IES PATENT-QFFIGE.

HIS RIGIEI'IA T0 GEORGE W. SAULPAW.

IMPROVEMENT IN VALVE-GEARS FOR ENGINES.

Specicatinu thrilling part of L: tters Patent No. 135,796, datedFebruary 1l, 1873.

To all 'whom it may concern:

Be it known that I, ROBERT MGC. FRYER, of Nashville, in the county ofDavidson and State of Tennessee, have invented a new and usefulImprovement in ValveLGear for Engines; and I do hereby declare that thefollowing is a full, clear, and exact description of the same, referencebeing had to the accompanyin g drawing forming part of thisspecitication, and in which* Figure 1 represents a rear elevation of adouble cylinder engine with my improved valve-gear applied, and Fig. 2 apartly sectional side elevation of the same.

Similar letters of reference indicate corresponding parts in bothiigures.

This invention relates to steam and other engines, constructedsubstantially as described i in Letters Patent No. 124,805, issued to meMarch 19, 1872, and in which a rocking beam or device having no Xedcenter, and constituting a cross or its equivalent, was used forconverting reciprocating motion into rotary motion, said cross havingits one end or arm connected with the crank to which it is required togive rotary motion, its opposite end or arm with a reciprocating crosshead or slide, and its two remaining arms with the reciprocatingpistons, respectively, of a double-cylinder engine, whereby a variablemotion was produced which avoided dead-centers as regards the action ofthe crank. My invention consists in a certain gear for operating'thevalves which control the admission and escape of the steam or otherpropelling medium to and from the pistons of such engines, said gearcomprising a similar rocking-beam or cross"connection having its one armpivoted to across head or slide, its opposite arm worked by an eccentricon the engine-shaft, and its remaining arms connected, respectively,with the valve-rods of the two cylinders, whereby the valves areoperated in exact unison with the engine-pistons to obtain a properaction for the latter when connected with the main or crank shaft, asdescribed. A

l In the accompanying drawing, AA' are the cylinders of .adouble-cylinder steam-engine,

of which are connected, respectively, by their rods a a' and links b b',with the opposite ends or arms c c' of a rocking beam or cross, B, havinno fixed center. The two other remaining arms d d' of the cross areconnected, respectively, as hereinbefore re ferred to, with a cross heador slide, C, and with a crank, D, ofthe main or engine shaft E.

In an engine-connection of this description, when force is appliedseparately to either of the pistons, the arm c or c' of the cross B inconnection therewith has a tendency to revolve the whole cross 5 but asthis is prevented by the slide C, which acts as a fulcrum, the oppositearm c or c' is forced to the right or to the left, as the case may be,and at the same time is forced in au opposite direction to the forceapplied to the piston. When equal force is applied in the same directionto both pistons the whole cross B acts as an ordinary connecting-rod, incombinationy with a crank and reciprocating motion, and has no directvibratory force. The crankl D being arranged as represented in relationwith the cross and pistons or their rods, steam is admitted at differentintervals to the pistons to rotate the en gine-shaft, being firstadmitted to act upon a single piston, and then upon both pistons, andtoward the conclusion of the stroke upon a single piston again, the twopistons moving at different velocities relatively with each other duringcertain portions of the stroke, all as described in my Letters Patenthereinbefore referred to.

In such an engine-connection., however the admission and exhaustionofthe steam to and from the enginecylinders may be adjusted,

it is important that theact-ion of the valves which controltheengine-pistons should be in accordance with the motion as derived fromthe cross B. To this end I employ a valve gear similar to theengine-beam or crosscounection, but deriving its motion from the rotarymovement of the main shaft E by means of an eccentric, D', and wherebyrotary motion is converted into reciprocating motion to operate thevalves of the two cylinders. G- Gr' are the valve-boxes of lthecylinders A A', and c e' the valve-rods, connected by links f f with thetwo opposite ends or arms h h', respectively, of a second rocking andreciprocating beam or cross, B', having no fixed center, and the tworemaining arms i t" of said cross being connected, respectively, with aslide, Q', 4and with the eccentricl D on the elif E of-etheengine-auditsoperating-cross YB or gine-shaftjEL By means `of this valvegear, itsequivalentLofthesecondary cross B or its the valves are operated intimely relation with equivalent, the eccentric D', the slide C', and theengine-pistons, as controlled by the cross the valve-rods e e', thewhole being arranged 13 of the en gine. in relation with each other foroperation sub- Under this arrangement a single eccentric, s tantially asspecified. .DQ ser-ves to operate 4two separate valves- ROBERT MCC.FRYER.

that is, one for either cylinder. Y

What is here claimed, and desired to be se- Vitnesses: l cured byLetters Patent, is- FRED. HAYNEs,

The combination, with the revolving'shaft BENJ. P. SHARP.

